#include<bits/stdc++.h>
using namespace std;
int n,q;
#define ll long long
const int mod=998244353,N=4e5+10;
ll s1[N][2],s2[N][2];int tg[N];
char c[N];
void sc(int p){
    for(int o=0;o<2;o++)
    s1[p][o]=s1[p<<1][o]+s1[p<<1|1][o],s2[p][o]=s2[p<<1][o]+s2[p<<1|1][o];
}
void build(int p,int l,int r){
    tg[p]=0;
    if(l==r){
        int t=(c[l]=='1');
        for(int z=0;z<2;z++)
        s1[p][z]=(t^z),s2[p][z]=l*(t^z);
        return;
    }
    int mi=(l+r)>>1;
    build(p<<1,l,mi),build(p<<1|1,mi+1,r);
    sc(p);
}
void rev(int p){
    swap(s1[p][0],s1[p][1]);
    swap(s2[p][0],s2[p][1]);
    tg[p]^=1;
}
void pd(int p){if(tg[p])rev(p<<1),rev(p<<1|1),tg[p]=0;}
void up(int p,int l,int r,int x,int y){
    if(x<=l&&r<=y)return rev(p);pd(p);
    int mi=(l+r)>>1;
    if(x<=mi)up(p<<1,l,mi,x,y);
    if(y>mi)up(p<<1|1,mi+1,r,x,y);
    sc(p);
}
int main(){
    while(~scanf("%d%d",&n,&q)){
        scanf("%s",c+1);
        build(1,1,n);
        for(int i=1,l,r;i<=q;i++){
            scanf("%d%d",&l,&r);
            up(1,1,n,l,r);
            ll xx=s2[1][0]*2-s1[1][0]*s1[1][0];
            printf("%lld\n",xx%mod);
        }
    }
    return 0;
}